export default {
  namespaced:true,
  
  state:() => ({
    //购物车的数组，用来存储购物车中每个商品的信息对象
    // 每个商品的信息对象，都包含如下6个属性
    // {goods_id,goods_name,goods_price,goods_count,goods_small_logo,goods_state}
    cart:JSON.parse(uni.getStorageSync('cart') || '[]')
  }),
  mutations:{
    addToCart(state,goods){
     const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
     if(!findResult){
       state.cart.push(goods)
     }else{
       findResult.goods_count++
     }
     this.commit('m_cart/saveToStorage')
    },
    saveToStorage(state){
      uni.setStorageSync('cart',JSON.stringify(state.cart))
    },
    //更新购物车中商品的勾选状态
    updateGoodsState(state,goods){
    const findResult = state.cart.find( x => x.goods_id === goods.goods_id)
    if(findResult){
      findResult.goods_state = goods.goods_state
       this.commit('m_cart/saveToStorage')
    }
    },
    //更新商品的数量
    updataGoodsCount(state,goods){
    const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
    if(findResult){
      findResult.goods_count = goods.goods_count
      this.commit('m_cart/saveToStorage')
    }
    },
    removeGoodsById(state,goods_id){
      //过滤器，将不需要删除的商品id留下
    state.cart = state.cart.filter(x => x.goods_id !== goods_id)
    this.commit('m_cart/saveToStorage')
    },
    //更新购物车中所有的商品勾选状态
    updataAllGodsState(state,newState){
      state.cart.forEach(x => x.goods_state = newState)
     this.commit('m_cart/saveToStorage')
    }
    
  },
  getters:{
    total(state){
      let c = 0
      state.cart.forEach(x => c += x.goods_count)
      return c
    },
    //计算购物车内商品的总数
    checkedCount(state){
     return state.cart.filter(x => x.goods_state).reduce((total,item) => { return total += item.goods_count },0)
    },
    //已勾选商品的总价格
    checkedGoodsAmount(state){
     return state.cart.filter(x => x.goods_state).reduce((total,item) => total += item.goods_count * item.goods_price,0).toFixed(2)
    }
    
  }
}
